The presence of segmented filamentous bacteria (SFB) in feces correlates with current production and the presence of microbial nanowires in MECs. A: relative abundance of operational taxonomic units (OTUs) in mucosal scrapes collected from C57BL/6NHsd mice; legend at right. B: Venn diagram depicting overlap between OTUs in feces of HSD mice (C57BL/6NHsd, A/JOlaHsd, and BALB/cAnNHsd mice, n = 8/strain); Jax mice (C57BL/6J, A/J, and BALB/cJ mice, n = 8/strain); and the ileal mucosal scrapes depicted in A. Unweighted (C) and weighted (D) principal component analysis of the fecal microbiota of C57BL/6, A/J, and BALB/c mice from Jackson (orange circles) and Harlan (red triangles) Labs (n = 8 mice/strain/vendor) and mucosal scrape material (blue squares) collected from C57BL/6NHsd mice (n = 4). E: scanning electron microscopic images of microbes present in MECs inoculated with feces from C57BL/6NHsd (HSD) or C57BL/6J (Jax) mice.